Once the linux build directory has been determined ($LINUX_DIR), try and

override the previous setting of the LINUX_KERNEL_RELEASE variable using
the release info from the Linux build directory.  Information comes from
the UTS_RELEASE C macro.  For kernel versions 2.6.18 and later this is
defined in include/linux/utsrelease.h.  For earlier kernel versions it is
defined in include/linux/version.h.

diff --git a/m4/as-linux.m4 b/m4/as-linux.m4
index 86902ec8bc20af68cca0ad0d86e833f8357a7769..468b5596a9c2e92b62de0ccb8395147ec718436b 100644 (file)
--- a/m4/as-linux.m4
+++ b/m4/as-linux.m4
@@ -78,6 +78,8 @@ AC_DEFUN([AS_LINUX],
 
        dnl find the kernel build tree for the given uname -r
        AS_LINUX_DIR()
+       dnl override kernel release uname -r value with info from build tree
+       AS_LINUX_OVERRIDE_KERNEL_RELEASE($LINUX_DIR)
        dnl find the kernel source tree from the build tree or --with-linuxsrcdir
        AS_LINUX_SRC_DIR($LINUX_DIR)
        dnl check if user supplied an EXTRAVERSION, and if not get from uname -r
@@ -226,8 +228,30 @@ AC_DEFUN([AS_LINUX_KERNEL_RELEASE],
         AC_MSG_NOTICE([Using $LINUX_KERNEL_RELEASE as the uname -r value])
 ])
 
+dnl replaces LINUX_KERNEL_RELEASE once the Linux build directory is known
+dnl first argument is the Linux build directory
+AC_DEFUN([AS_LINUX_OVERRIDE_KERNEL_RELEASE],
+[
+       INCDIR="$1/include"
+       UTSINC="${INCDIR}/linux/utsrelease.h"
+       if ! test -f "${UTSINC}"; then
+               UTSINC="${INCDIR}/linux/version.h"
+       fi
+       if test -f "${UTSINC}"; then
+               RELEASE=`echo UTS_RELEASE | cat "${UTSINC}" - |
+                       /lib/cpp -I "${INCDIR}" | tail -n 1 |
+                       sed 's/^"\(.*\)"$/\1/'`
+               if test "${RELEASE}" != "UTS_RELEASE" -a "${RELEASE}" != "" \
+                       -a "${RELEASE}" != "${LINUX_KERNEL_RELEASE}"; then
+                       AC_MSG_NOTICE([Overriding uname -r value with ${RELEASE}])
+                       LINUX_KERNEL_RELEASE="${RELEASE}"
+               fi
+
+       fi
+])
+
 dnl allow for specifying a machine (uname -m) to build for
-dnl use uname -, of running one if not specified
+dnl use uname -m, of running one if not specified
 dnl store result in LINUX_MACHINE
 AC_DEFUN([AS_LINUX_MACHINE],
 [